1. Field of the Invention
The present invention is related to bicycles and in particular, to bicycle designs which are easier to ride.
2. Description of the Prior Art
Conventional bicycles, often referred to as diamond frame bicycles, are available in many shapes and sizes. Conventional bicycle frames include a horizontal chain stay running between the axle of the rear bicycle wheel and the bottom bracket through which the pedals are mounted for rotation. The seat tube, which supports the seat or saddle, is typically welded to the bottom bracket. The down tube, running from the bottom bracket to the head tube within which the front wheel rotates for steering, is also typically welded to the bottom bracket. A top tube, running from the rear wheel axle to the head tube, also serves to stabilize the seat tube and may be made from a seat stay between the rear axle and the seat tube plus an upper tube from the seat tube to the head tube.
Conventional bicycle frames of this type are called diamond frames because the seat tube, chain stay, and seat stay form a first triangle and the seat tube, down tube and upper tube generally form a second, connected triangle with the down and upper tubes connected close to each other at the head tube. In such conventional bicycle frames, the bottom bracket through which the pedals are mounted for rotation, serves as a common joint between the triangles and is welded or otherwise affixed to the chain stay, seat tube and down tube. The top tube may be mounted lower towards the ground in versions requiring a lower stand-over height, that is, the height of the bicycle frame between a rider's legs when standing with both feet on the ground.
When conventional bicycles are adjusted for a particular rider, the seat tube is typically extended so that the seat height allows the rider to extend one leg to reach the related pedal in it's furthest forward position. The proper full leg extension while pedaling, called herein the “proper full leg extension for pedaling”, includes a minor bend at the knee so that the leg is not locked. When riding, the rider is typically leaning forward. When stopped, the rider is typically required to extend the toes on one foot to reach the ground and often will tilt the bicycle toward the foot touching the ground in order to better reach the ground. That is, when stopped, the seat is typically positioned too high for the rider to comfortably put both feet flat on the ground without tilting the bicycle.
Recumbent bicycles were developed to reduce the strain on the rider's back by moving the bottom bracket and pedals further forward. This permits the rider to lean back and to operate the pedals at a different, less stressful angle. Allowing the rider to lean back, and moving the bottom bracket and pedals further forward, increases the wheelbase of the bicycle. When stopped, the rider can typically reach the ground with both feet. Some riders consider this to be an awkward position because the rider's weight is behind the rider's feet rather than above the rider's feet as it would be in a conventional bicycle. In addition, the rider cannot stand up while pedaling as is commonly done for increased performance for example when pedaling uphill.
One currently popular variation for bicycle frames is called the “chopper” in which the bottom bracket and pedals are moved forward from the conventional bicycle frame position, but not as far forward as they would be in a recumbent bicycle. The rider sits relatively erect with the handle bars extended toward the rider. Conventional chopper designs typically provide neither the comfort and convenience of a conventional bicycle frame design nor the reduced back strain of the recumbent designs.
What is needed is a bicycle design in which the bicycle is comfortable to learn to ride, to stand with and to ride. In particular, what is needed is a bicycle frame design in which the rider can sit upright, stand up while pedaling if desired and being able to put one or both feet flat on the ground when stopped and the seat is adjusted for proper leg extension for pedaling.